bg-image($url)
    background-image url($url + '@2x.png')
    @media (-webkit-min-device-pixel-ratio: 3), (min-device-pixel-ratio: 3)
        background-image url($url + '@3x.png')
no-wrap()
    text-overflow ellipsis
    overflow hidden
    white-space nowrap
extent-click()
    position relative
    &:after
        content ''
        position absolute
        top -10px
        left -10px
        right -10px
        bottom -10px
line-hidden($number)
    overflow hidden
    text-overflow ellipsis
    display -webkit-box
    -webkit-line-clamp $number
    -webkit-box-orient vertical